Damaged usb interface

[serbar]

Hello.

I have an usb interace from a car diagnostic tool that i damaged. I am trying to fix this since the new one is very expensive.

Dont have welding skills on PCB so contacted a skiled friend to do this job.

Let it fall down and some SMD components got loose from their welding but i could find new ones to be welded again on the interface PCB, except one that i am not sure what is.

I hope someone give me a clue to what is this component and perhaps i can find one to try fixing the PCB.

Here is the picture of a similar intact PCB from a friend of mine, the component is next to a USB type B port. It has a red mark around it, it is marked as "E2" on the PCB.

I contacted the suplier thy dont provide schematics neither information on it, they just sell new complet unit.

This is an important working tool for me.

Thanks in advance for help.

 

[serbar]

Sorry.

Here is the atached picture of the PCB.

Thanks.

 

[itsmoked]

3 terminal
not a capacitor
probably a transient suppressor.

Hopefully someone will come along soon and know.

It's called soldering NOT welding.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[LiteYear]

Don't know, but here's some clues:

1. The 'E' designator is unusual. The IEEE standard uses it for "terminals", which doesn't help.
2. That's a good spot for a TVS, but the chip next to the USB port (DA1) is a USB6B1, which actually has TVS built-in. The only external components it recommends is a capacitor.
3. The U1 chip is a quad 2-input AND gate, and the pin which connects to the centre of the component in question is ground.

 

[Comcokid]

The tan color leads me to believe it is a capacitor, specifically a type that feeds-through with a center contact to ground for noise bypassing. From the size of the other components the part is a 1206 size.

The question is the value. An example, made by Johanson can be found at

http://www.digikey.com

as 709-1013-1-ND 0.1uF 50V or 709-1107-1-ND 1000pF 100V.

These are used to supress internal noise from getting out of the unit, or for keeping external noise from getting in the unit. Being located close to the USB jack indicates that it is bypassing noise from either one of the I/O lines of the incomming power. Usually not absolutely necessary for the device to function, but if not replace then a small wire will have to be placed from one end terminal pad to the other end terminal pad.

 

[VEBill]

Solder joints are quite strong, typically much stronger than the lamination strength of the PCB traces to the PCB substrate. If various components have flown off the PCB due to impact and been lost, then it's fairly likely that the PCB itself will have suffered significant damage. Be prepared for a nasty combination of intricate repairs and risk of repeated disappointment.

 

[serbar]

Thanks for information.



So i think most opinions point out to a capacitor for noise supression?


If i place a wire instead of the component which of the three terminals should be connected with?

Thanks.

 

[OperaHouse]

Got one more thing for you to quote. FORM FOLLOWS FUNCTION

Must have missed something. If the part fell off, how are we liiking at it? We can not view this directly. If it is three terminal device and a filter, the lead connected to ground or common can be ignored.

 

[IRstuff]

"If i place a wire instead of the component which of the three terminals should be connected with?"

If you're absolutely lucky, nothing will happen. If not, you may fry something.

TTFN
faq731-376

Need help writing a question or understanding a reply? forum1529

 

[Noway2]

It has been a few years ago, but I did design a (working) USB interface circuit. From what I recall, the power lines had capacitors and chokes to provide proper hold up. The power was applied through transistors with a range of RDS_on where the voltage drop was measured to protet against overload. The data lines (D+/D-) (I think that it was on the data lines) had diodes, in a two diode, three terminal device though I can't recall if it was common cathode or anode to prevent over voltage. When you mentioned 3 terminal device this was my first thought.